Yuuya Tenjou has been bullied all his life. Then he discovers a door to another world. Powerful weapons. Vicious monsters. It all seems like a fantasy game! And when he returns to his world, he realizes that his leveling up comes with him.

Yuya responds to Princess Lexia's marriage proposal and receives an invitation to an audience at the royal palace. At the same time, he returned to the Ôsei Academy.

As Yuuya tries to find a way to level up in the Darkest Regions, he comes across a Black Fenrir pup. Yuuya Tames him, names him Night, and brings him home to live together as family. Side by side, they explore the Darkest Regions...and also go for walks.

The study trip isn’t at all what Yuuya and the others had imagined. They’re faced with a series of unexpected challenges. Later, Yuuya meets with Lexia and her guards so they can escort him to his audience with the king, but Night begins acting strangely.

The Director still has designs on Yuuya, but he's too busy studying for his upcoming exams to worry about it. Kaori comes over to help him with math, and then...! Later, Yuuya takes advantage of a short school holiday to head for the royal capital.

Lexia is determined to make the most of Yuuya's visit to the capital in spite of everything that's happened. When Luna and Lexia take Yuuya out of the castle to show him around town, the signboard of a certain guild catches his eye.

Reigar has been captured and must pay the price for his crimes, but Yuuya still has to deal with the enemy girl who proved to be just as strong as he is.